1. Field of the Invention
The present invention relates generally to the production of semiconductor substrates, and more particularly to an apparatus and a method for producing semiconductor substrates protecting against unwanted deposits formed on a treating chamber. Hereinafter, the producing apparatus and method will be referred to as the apparatus and the method, respectively.
2. Description of the Prior Art
In producing semiconductor substrates by a reactive ion etching (RIE) method or a chemical vapor depositing (CVD) method, the inside walls of the apparatus are liable to deposits which consist of SiO.sub.2, and/or organic polymers. These deposits emit impure gases which not only stain the semiconductor substrates but also break a gaseous equilibrium in the apparatus, thereby unfavorably affecting the quality thereof. In addition, the deposits are likely to peel off onto the semiconductor substrates and spoil the patterns thereon, thereby reducing the yields of semiconductor substrates. As the patterns on the semiconductor substrates become finer and finer, the reduced yields become more serious.
Accordingly, one practise for removing the deposits is to stop the operation periodically so as to clean the deposits from the inside walls of the apparatus with an organic solvent (the wet cleaning method), and another practise is to disassemble the apparatus into components parts and clean then by ultrasonic wave (the ultrasonic cleaning method). A further practise is to prevent impurities from being deposited on the inside wall of the apparatus by use of plasma (the plasma cleaning method).
These three practises are disadvantageous in that the operation must be stopped for each cleaning, thereby reducing the operating speed. In mass-producting process the frequent suspensions of the operation reduces the productivity even though each break is a short term.